Host identity protocol server address configuration

Abstract

A method of facilitating access to a Host Identity Protocol security procedure by a host connected to a moving network, where the moving network comprises a Host Identity Protocol server responsible for allocating local IP addresses to attached hosts. The method comprises registering at a rendezvous server an IP address prefix for use by said Host Identity Protocol server in allocating said local addresses, together with an externally reachable IP address of the Host Identity Protocol server. The registered IP address prefix is used at the rendezvous server to forward received I 1 messages to the Host Identity Protocol server. The rendezvous server controls the allocation and registration of address prefixes to Host Identity Protocol servers in order to prevent collision of local IP addresses.

1 . In a network comprising a server responsible for allocating local IP addresses to attached hosts, a method comprising:
 registering at a rendezvous server an IP address prefix for use by the server in allocating said local addresses, together with an externally reachable IP address of the server; and   using the registered IP address prefix at the rendezvous server to forward received I 1  messages to the server, wherein   said rendezvous server controls the allocation and registration of address prefixes to servers in order to prevent collision of local IP addresses.   
     
     
         2 . The method according to  claim 1 , wherein the server is a Host Identity Protocol proxy, and said hosts are legacy hosts. 
     
     
         3 . The method according to  claim 2 , further comprising registering a Host Identity or Host Identity Tag of the server at the rendezvous server together with said IF address prefix. 
     
     
         4 . The method according to  claim 1 , wherein the server is a Host Identity Protocol mobile router, and said hosts are HIP hosts. 
     
     
         5 . The method according to  claim 1 , wherein said rendezvous server controls the allocation and registration of address prefixes to servers by selecting an unallocated IP address prefix from a pool of IP address prefixes, registering the selected prefix in respect of the registering server, and notifying the registering server of the selected and registered IP address prefix. 
     
     
         6 . The method according to  claim 1 , wherein said rendezvous server controls the allocation and registration of address prefixes to servers by receiving a proposed IP address prefix from the registering server and accepting or rejecting the proposal based upon already registered prefixes. 
     
     
         7 . The method according to  claim 6 , further comprising, following a rejection of a proposed IP address prefix by the rendezvous server, selecting an alternative prefix at the server, and sending this to the rendezvous server. 
     
     
         8 . The method according to  claim 6 , further comprising, following a rejection of a proposed IP address prefix by the rendezvous server, selecting an alternative and unallocated prefix at rendezvous server and sending this to the server. 
     
     
         9 . The method according to  claim 1 , wherein said rendezvous server is one of a set of cooperating rendezvous servers, the rendezvous servers exchanging data identifying allocated IP address prefixes to prevent IP address prefix collision between rendezvous servers. 
     
     
         10 . An apparatus configured to operate as a rendezvous server for establishing sessions between hosts, the apparatus comprising:
 a registration database;   a receiver for receiving a registration request from a server, the server being responsible for allocating local IP addresses to attached hosts;   a registration unit for responding to receipt of a registration request by registering in said registration database an IP address prefix for use by the server in allocating said local addresses, together with an externally reachable IP address of the server; and   a message handling unit for using the registered IP address prefix to forward received I 1  messages to the server,   wherein said registration unit is configured to control the allocation and registration of address prefixes to servers in order to prevent collision of local IP addresses.   
     
     
         11 . The apparatus according to  claim 10 , wherein said registration unit is configured to control the allocation and registration of address prefixes to servers by allocating to the server an unallocated IP address prefix from within an IP address prefix pool, the apparatus further comprising a sending unit for sending the allocated IP address prefix to the server. 
     
     
         12 . The apparatus according to  claim 10 , wherein said registration unit is configured to control the allocation and registration of address prefixes to servers by identifying within said registration request an IP address prefix proposed by the server and rejecting that prefix if the prefix is registered for another server. 
     
     
         13 . The apparatus according to  claim 12 , said registration unit being further configured, upon rejection of a proposed IP address prefix, to either send an alternative, available prefix to the server, or to consider an alternative proposal from the server. 
     
     
         14 . The apparatus according to  claim 10 , said registration unit being configured to exchange, with other associated rendezvous servers, data identifying allocated IP address prefixes to prevent IP address prefix allocation collision between rendezvous servers. 
     
     
         15 . The apparatus according to  claim 10 , wherein the server is one of a Host Identity Protocol proxy and a Host Identity Protocol mobile router. 
     
     
         16 . An apparatus, the apparatus comprising:
 a registration unit for registering at a rendezvous server an IP address prefix for use by the apparatus in allocating local IP addresses within a subnetwork, together with an externally reachable IP address, and a Host Identity or a Host Identity Tag, of the apparatus,   the registration unit being configured to receive from the rendezvous server the registered IP address prefix.